The invention relates to fastener placing apparatus for placing fasteners of the type comprising a threaded first part which is pulled towards and/or into a second part to place the fastener. Such fastener placing apparatus comprises an abutment for abutting the second part of a fastener to be placed, and a threaded member for engaging with the threaded first part of the fastener, the threaded member being rotatable and reciprocable with respect to the abutment. Such apparatus is hereinafter referred to as "fastener placing apparatus of the type defined," and one form is described in detail in my U.S. Pat. No. 3,861,014. It has been found that, in such tools in which the threaded mandrel has no permissible movement sideways from alignment with the tool axis, the rate of breakage of mandrels in use of the tool is unexceptably high, due to initial mis-alignment of the tool causing too much sideways bending stress on the mandrel. It is an object of this invention to reduce the breakage rate of mandrels consequent upon initial mis-alignment of the tool.